Hydrogenated olefin sulfonate-alkyl-1,2-glycol detergent compositions

ABSTRACT

HIGH PERFORMANCE DETERGENT COMPOSITIONS COMPRISE A MIXTURE OF HYDROGENATED OLEFIN SULFONATES AND AN ALKYL-1, 2-GLYCOL.

United States Patent Office Patented Dec. 5, 1972 -wm m M...

ABSTRACT OF THE DISCLOSURE High performance detergent compositionscomprise a mixture of hydrogenated olefin sulfonates and an alkyl-l,2-glycol.

BACKGROUND OF INVENTION Recent concern over water pollution has resultedin significant changes in the active ingredient of modern detergents.Extensive and expensive research has been directed at discoveringsuitable detergent compounds which are both readily biodegradable andpossess high detersive properties.

Heretofore, however, known commercial detergent compounds whichpossessed high detersive properties were not as biodegradable asdesired; and, on the other hand, the readily biodegradable detergentcompounds were not as desirable in terms of detersive properties.

In direct contrast to the aforementioned commercially availabledetergents the novel compositions of the present invention are bothreadily biodegradable and exhibit excellent detergent properties. Inaddition, the novel detergent compositions as described herein arereadily and economically produced on a commercial scale basis.

DESCRIPTION OF INVENTION It has now been found that superior detergentcompositions comprise a mixture of straight-chain hydrogenated olefinsulfonates containing from 10 to 24 carbon atoms, and straight-chainalkyl 1,2-glycols wherein the alkyl radical contains from 10 to 20carbon atoms. In particular, the performance of the described mixture issignificantly greater than would be predicted from a knowledge of theperformance of the individual components as well as other compounds.

The term hydrogenated olefin sulfonates as used in the present inventiondefines the complex mixture obtained by the S sulfonation ofstraight-chain olefins containing to 24 carbon atoms and subsequentneutralization, hydrolysis and hydrogenation of the sulfonation reactionproduct. This complex mixture may contain hydroxyalkane, alkane andalkene sulfonates as its major components and a lesser proportion ofdisulfonated product.

While the general nature of the major components of the complex mixtureis known, the specific identity and the relative proportions of thevarious hydroxy, sulfonate, and disulfonate radicals and double bondlocations are unknown. Accordingly, a determination of the entirechemical makeup is exceedingly difficult and has not heretofore beensuccessfully accomplished. The mixture is best defined by the processused for producing it.

Optimum detergent characteristics are exhibited by a hydrogenated olefinsulfonate obtained by SO -air sulfonation of C1044 straight-chainolefins with an SO :air volume ratio of about 1 to 50-100 and an sOzolefin mol ratio of .95 to 1.15; neutralization and hydrolysis of thesulfonation reaction product at temperatures of 145 to 200 C. using oneequivalent of base per mol of S0 consumed in the sulfonation step;treatment of the sulfonate product with oxygen or hydrogen peroxide; andhydrogenation in the presence of Raney nickel or palladium on carboncatalysts at temperatures of from to 120 C.

In addition to the preferred straight-chain alpha-olefins from waxcracking suitable olefin starting materials include straight-chainalpha-olefins produced by Ziegler polymerization of ethylene, orinternal straight-chain olefins prepared by catalytic dehydrogenation ofnormal paraflins or by chlorination-dehydrochlorination of normalparaflins. The olefins may contain from 10 to 24 carbon atoms, usually13 to 22 carbon atoms, and preferably 15 to 18 carbon atoms permolecule. Olefin mixture should have an average molecular weight of atleast about 200.

The amount of S0 utilized in the sulfonation reaction may be varied butis usually within the range of 0.95 to 1.25 mols of S0 per mol of olefinand preferably in the range 1:1 to 111.15. Greater formation ofdisulfonated products is observed at higher SO :olefin ratios.Disulfonation may be reduced by carrying the sulfonation reaction onlyto partial conversion of the olefin, for example by using SO :olefinratios of less than 1 and removing the unreacted olefins by a deoilingprocess. The unreacted olefins may be removed by extracting the reactionproduct with a hydrocarbon such as pentane.

In order to obtain a product of good color, the S0 employed in thesulfonation reaction is generally mixed with an inert diluent or with amodifying agent. Inert diluents which are satisfactory for this purposeinclude air, nitrogen, S0 dichloromethane, etc. The volume ratio of S0to diluent is usually within the range of 1:100 to 1:1.

The reaction product from the sulfonation step may be neutralized withaqueous basic solutions containing compounds such as hydroxides,carbonates and oxides of the alkali metals, alkaline earth metals andammonium. In the preferred method, suficient neutralizing solution maybe added to provide for neutralization of the hydroxyalkane sulfonicacids formed by sulfone hydrolysis. Generally, one equivalent of basefor each mol of S0 consumed in the sulfonation reaction is added to thesulfonation reaction product.

The proportion of hydroxyalkane sulfonates to alkene sulfonates in thehydrolyzed neutralized product may be varied somewhat by the manner inwhich neutralization and hydrolysis are carried out. Thus reducedamounts of hydroxyalkane sulfonates are obtained by carrying out theneutralization and hydrolysis at temperatures in the range of l45200 C.while higher yields of hydroxy sulfonate are favored by carrying out theneutralization and hydrolysis at temperatures below C. Suitablehydrolysis temperatures range from about 100 to 200 C.

The straight-chain alkyl 1,2-glycols suitable for producing theexcellent detergent compositions of the present invention may berepresented by the formula wherein R is a straight-chain alkyl radicalcontaining from 8 to 18 carbon atoms and preferably 9 to 12 carbonatoms. The alkyl glycol component need not be limited to compoundscontaining alkyl radicals of a single set carbon number but may includemixtures thereof, such as a mixed C C alkyl 1,2-glycol. As used in thepresent specification the notation C C etc. refers to the total numberof carbon atoms in the alkyl 1,2-glycol.

Suitable straight-chain glycols include, but are not limited to alkyl1,2-glycols where the alkyl radical is selected from the following:n-octyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl, n-tridecyl,n-tetradecyl, n-pentadecyl, n-hexadecyl, n-heptadecyl, n-octadecyl, andmixtures thereof.

The selected glycols or mixtures thereof may comprise from 1 to 40 partsper hundred parts by weight of hydrogenated olefin sulfonate of thedetergent composition. The most desirable ratio is usually from 5 to 30parts per hundred parts by weight of olefin sulfonate.

The following examples describe the preparation of hydrogenated olefinsulfonates, their precursor olefin sulfonates and the novel detergentcompositions of the present invention.

Example l.--Preparation of olefin sulfonate The reactor used for thissulfonation consisted of a continuous falling film-type unit in the formof a vertical water-jacketed tube. Both the olefin and the S air mixturewere introduced at the top of the reactor and flowed concurrently downthe reactor. At the bottom the sulfonated product was separated from theair stream.

The feed was a straight-chain l-olefin blend produced by cracking highlyparaflinic wax and having the following composition by weight: 1%tetradecene, 27% pentadecene, 29% hexadecane, 28% hcptadecene, 14%octadecene and 1% nonadecene. This material was charged to the top ofthe above described reactor at a rate of 206 pounds/hour. At the sametime 124.2 pounds/hour of S0 diluted with air to 3% by volumeconcentration of S0 was introduced into the top of the reactor. Thereactor was cooled with water to maintain the temperatuure of theefiiuent product within the range of 43-46 C. The average residence timeof the reactants in the reactor was less than two minutes.

After passing out of the reactor the sulfonated product was mixed with612 pounds/hour of 11.2% aqueous caustic and heated to 145-150 C. in atubular reactor at an average residence time of 30 minutes. This stepneutralized the sulfonic acids contained in the sulfonation reactionproduct, hydrolyzed the sulfones to hydroxy sulfonic acids andneutralized the hydroxy sulfonic acids. Olefin sulfonates were producedat the rate of 463 pounds per hour as an aqueous solution having a 45%by weight solids content and a pH of 10.8.

A portion of this product was analyzed and shown to be made up of thesodium salts of alkene sulfonic acids, hydroxy alkane sulfonic acids,and disulfonic acids. These three major components were present in aweight ratio of about 50/35/15.

Example 2.--Preparation of C1540 olefin sulfonates A straight-chainl-olefin mixture produced by cracking a highly parafiinic wax andcontaining 1% tetradecene, 18% pentadecene, 17% hexadecene, 1 6%heptadecene, 16% octadecene, 14% nonadecene, 13% eicosene, andheneicosene was processed following the procedure in Example 1.

Example 3.-Preparation of hydrogenated olefin sulfonates The apparatusfor this hydrogenation consisted of a 1-liter Magne-Drive autoclaveequipped with an accumulator, a constant pressure regulator, and atemperature recording means. The product of Example 1 was diluted withwater to a 26% solids concentration and was filtered to remove a traceamount of insoluble material. The pH was adjusted to a value of 6.5-7.5by neutralizing the slight excess of NaOH used in the neutralization andbydrolysis step with H SO and 100 parts of 30% hydrogen peroxide wasadded to 3850 parts of the filtered 26% solution in an open glassvessel. This mixture was heated to 80 C. and stirred for one hour atthis temperature, after which time no hydrogen peroxide remained. Aftercooling this solution to room temperature, 650 g. of it was charged tothe previously described autoclave along with 8.5 g. of Raney nickel.The system was purged with nitrogen and then with hydrogen. It was thenpressured with hydrogen to 50 p.s.i.g. The autoclave was warmed to 100C. at which temperature hydrogen was again introduced to bring thepressure up to 100 p.s.i.g. The hydrogen pressure was maintainedconstant at 100 p.s.i.g. throughout the run. After one and one-halfhours of stirring at this temperature and pressure, and at which timethere was no additional hydrogen uptake, the solution was cooled toabout 70 C., filtered, and then allowed to cool.

Example 4.-Preparation of hydrogenated olefin sulfonates The product ofExample 2 was reduced as in Example 3 to give a substantially reductionof double bonds in the olefin sulfonate.

The hydrogen peroxide treating step prior to hydrogenation increaseshydrogenation efiiciency. The olefin sulfonate prior to such treatmentcontains unidentified compounds which poison hydrogenation catalysts.Without the hydrogen peroxide pretreat catalyst consumption is muchhigher. Other oxidizing agents may be used instead of hydrogen peroxidein the pretreating step, preferably oxidizing agents which leave nosolid residues in the product such as elemental oxygen or air.

In addition to the Raney nickel exemplified, a wide variety of knownhydrogenation catalysts may be used in the hydrogenation step. Theseinclude the noble metals and various forms of nickel other than Raneynickel such as nickel on kieselguhr, and other supported nickelcatalysts. Palladium on carbon and ruthenium on alumina are efiectivenoble metal catalysts, although Raney nickel and palladium on carbon arepreferred catalysts.

The amount of catalyst employed in the hydrogenation of olefinsulfonates may vary in a range from about 0.05 to 30% by weight based onthe olefin sulfonate present. Increasing the amount of catalyst willusually result in a shortening of the time necessary for completehydrogenation.

The hydrogenation reaction is usually carried out at temperatures fromabout 20 C. to 200 C. and preferably 70 C. to C. At temperaturesappreciably above 200 C. unnecessary hydrogenation of hydroxyalkanesulfonates and hydrogenative degradation of the product tend to occur.

Hydrogen pressure during the reaction is not a critical variable.Reduction may be carried out at pressures varying from less thanatmospheric to 5000 p.s.i.g., but preferably from 30' to 200 p.s.i.g.

In Examples 3 and 4 above hydrogenation of the alkene sulfonatecomponent of the neutralized sulfonation reaction mixture to alkanesulfonate was essentially complete. Partial hydrogenation of the olefinsulfonate to the extent that at least 50% of the alkene sulfonate isconverted to alkane sulfonate yields a hydrogenated olefin sulfonatesuitable for use in producing high quality non-soap detergent bars.=Partial hydrogenation may be accomplished by proceeding as in Example 3but discontinuing the hydrogenation reaction before hydrogen take upceases. Partial hydrogenation can also be carried out by subjecting theolefin sulfonate to hydrogenation after neutralization but prior tohydrolysis.

Example 5.'Preparation of partially hydrogenated olefin sulfonate Theprocedure of Example 3 was followed except that reduction was allowed tocontinue for only 30 minutes. The product was worked up as before.Analysis of a small aliquot by bromine number titration showed that 55%of the double bonds originally contained had been saturated.

Example 6.--Hydrogenation of an unhydrolyzed olefin sulfonatel-hexadecene was sulfonated in a continuous fallingfilm reactor with SO/olefin mol ratio of about 1.2. The product from this reaction, 184 g.was dissolved in 198 g. of dioxane to give a 48% solution.

50 g. of this 48% solution was heated with stirring to 60 C. Then 2.1 g.of 34% hydrogen peroxide was added. Stirring was continued at thistemperature for one hour. The solution was allowed to cool to roomtemperature.

of the hydrogen peroxide treated material, 17.3 g. was diluted to 50 ml.with dioxane and charged to a 200 ml. Fischer-Porter bottle along with0.80 g. of palladiumon-carbon hydrogenation catalyst. The mixture washeated to 24-26 C. and pressured to 50.5 p.s.i.g. with hydrogen. After30 minutes of reaction, the pressure had dropped 18.4 p.s.i.g. Nofurther drop in pressure occurred after this time. This pressure dropcorresponds to hydrogenation of 31% of the original olefin-S0 reactionproduct.

The hydrogenated material was filtered to remove the catalyst. Thedioxane was removed by evaporation at temperatures below 40 C. underreduced pressure. In

this way, there was obtained 8.3 g. of a low melting solid. A portion ofthis solid, 6.4 g. was mixed with 2.0 g. of 50% aqueous sodium hydroxidein 35 ml. of water and heated at 150-155 C. for two hours. The water wasthen removed by evaporation. A bromine number analysis of the finalproduct indicated that about 25% of the Product was unsaturated.Accordingly, the calculated weight ratio of hydroxyalkane, alkene andalkane sulfonates would be 44/25/31, respectively.

Example 7.--Preparation of detergent composition A sample ofhydrogenated olefin sulfonates produced in accordance with Example 4 wasformulated with an alkyl 1,2-glycol and other ingredients into ahousehold detergent composition. The percentages of the variousingredients based on the total weight of the formulation were:

The detergent formulation was dissolved in water to a 0.15% by weightconcentration and evaluation by use of the Hand Dishwashing Test." TheHand Dishwashing Test" is an eifective means for evaluating thedetersive characteristics of detergent compositions and is based on aprocedure presented at the ASTM D-12 Subcommittee on Detergents, Mar.10, 1949, New York, NY. The test measures under simulated home washingconditions the number of plates or dishes washed before foam collapses.

The composition of Example 7 gave an excellent rating of 32 plates bythis test. In comparison a sample of olefin sulfonates prepared inaccordance with Example 1 was formulated as above, and tested, but gavea rating of only 25 plates.

Example 8 A sample of hydrogenated olefin sulfonates was pre pared inaccordance with Example 4 and separated into three portions. The firstportion, 25 parts, was dissolved in 75 parts of water. This solution wasevaluated at 0.15% concentration by the dishwashing test and gave a lowrating of only 6 plates. A similar solution of olefin sulfonatesprepared in accordance with Example 1 was dissolved in water in asimilar manner and gave a rating of 20 plates.

Example 9 The second portion from Example 8 was combined with 19 partsof C -C alkyl 1,2-glyco1 per hundred parts of hydrogenated olefinsulfonate, and 25 parts of this mixture was dissolved in 75 parts ofwater. Evaluation of this composition at 0.15% concentration gave arating of 11 plates, an improvement of almost 100%.

6 Example 10 TABLE I Example Glycol Amount 1 Plates 4/98 30 2.0/105 3230/95 29 0/105 24 30/95 30 16 None.-- 0/100 24 Parts of glycol/parts ofhydrogenated olefin sulfonate.

Another effective means for measuring the properties of detergentcompositions is known as the Bench Foam Test. In a representative testseries solutions of .05 by weight concentration of formulations wereprepared in aliquots of 1000 ml. The test consisted of mechanicallystirring the test solutions, after heating to 120:10" F., in a 2000 ml.beaker for one minute, and measuring the foam height in mm. at 0 andafter 10 minutes. Foam heights of 11 and 8 mm. at 0 and 10 minutes areconsidered satisfactory.

The Bench Foam Test correlates well with the dishwashing test. Forexample, a test on a sample prepared in accordance wtih Example 8 gavefoam heights of 9 and 7 mm. at 0 and 10 minutes respectively. Foamheights of 13 and 11 mm. were observed for a sample prepared inaccordance with Example 9 in a ratio of 20 parts of C -C alkyl1,2-glycol per parts of hydrogenated olefin sulfonate.

A sample prepared in accordance with Example 10 in a ratio of 10 partsof 0 -0 alkyl 1,2-glycol per parts of hydrogenated olefin sulfonate gavefoam heights of 16 and 15 mm. respectively.

Similar tests were run on different water concentrations, amounts ofglycols and type of glycols and the results are 2 Made up to 10%concentration in water.

The C11, C12, C13, C14, C15 C16, C17 and C alkyl 1,2-glycols whensubjected to the dishwashing and Bench Foam tests exhibit improveddetersive characteristics similar to the results of their respectivemixtures.

Additional compatible ingredients may be incorporated into the detergentcompositions prepared in accordance with the present invention toenhance their detergent properties. Particularly effective is theincorporation of certain pentavalent phosphoricacid salts. For example,suitable phosphates would include, but are not limited to: sodiumtripolyphosphate, potassium tripolyphosphate, ammonium tripolyphosphate,tetrasodium pyrophosphate, tetrapotassium pyrophosphate, trisodiumphosphate, tripotassium phosphate, ammonium phosphate, sodiumhexametaphos phate, potassium hexametaphosphate, ammoniumhexametaphosphate, monosodium orthophosphate, monopotassiumorthophosphate, disodium orthophosphate, dipotassium orthophosphate andthe like.

An effective amount of alkali pentavalent phosphoric acid salt usuallycomprises from about 0.2 to 3 parts per part by weight of hydrogenatedolefin sulfonate. Preferably, the ratio is 1 to 2 parts per part byweight of hydrogenated olefin sulfonate.

Other compatible ingredients which may be incorporated into thedetergent compositions of the present invention include anticorrosion,antiredeposition, chemical bleaching and sequestering agents; opticalwhiteners and certain inorganic salts other than phosphate, such asinorganic sulfates, carbonates or borates. The appropriate quantitiesand compositions of these additives, agents and builders are welldescribed in the art.

As will be evident to those skilled in the art, various modifications onthis process can be made or followed, in the light of the foregoingdisclosure and discussion, without departing from the spirit or scope ofthe disclosure or from the scope of the following claims.

I claim:

1. A detergent composition having improved detersive characteristicsconsisting essentially of (a) a mixture of hydrogenated olefinsulfonates obtained by sulfonating straight-chain olefins containingfrom 10 to 24 carbon atoms with S wherein said sulfonated olefins aresubsequently subjected to, in any desired sequence, the steps of:

(1) treating with an oxidizing agent selected from the group consistingof hydrogen peroxide, elemental oxygen, and air in an amount suflicientto improve the hydrogenatability thereof and hydrogenating said treatedsulfonated olefins with a conventional hydrogenation catalyst at atemperature of from about 20 to 200 C., said catalyst being employed inan amount of from about 0.05 to 30% by weight based upon the olefinsulfonate content, the hydrogenation being allowed to proceed until from50 to 100% of the unsaturated carbon-carbon double bonds therein aresaturated;

(2) hydrolysis of the sultone content of said mix- 0 ture at atemperature of from about 100 to 200 C.; and

(3) neutralization of said mixture; and (b) a glycol, of the formulaR1-CHCH5 wherein R is a straight-chain alkyl radical containing from 8to 18 carbon atoms, in a ratio of l to parts per hundred parts ofhydrogenated olefin sulfonate.

2. A detergent composition of claim 1 which contains as an additionaladjuvant an alkali metal pentavalent phosphoric acid salt in an amountof from 0.2 to 3 parts by weight of hydrogenated olefin sulfonate.

3. A detergent composition as in claim 1 wherein the straight-chainolefins are alpha-olefins.

4. A detergent composition as in claim 3 wherein the straight-chainolefins contain from 15 to 20 carbon atoms.

5. A detergent composition as in claim 4 wherein the glycol is presentin an amount of from 5 to 30 parts of hydrogenated olefin sulfonates.

6. A detergent composition as in claim 5 wherein from to percent ofcarbon-carbon double bonds are hydrogenated.

7. A detergent composition as in claim 5 wherein R is selected from thegroup consisting of octyl, nonyl, undecyl, decyl, dodecyl, and mixturesthereof.

References Cited UNITED STATES PATENTS 2,956,025 10/1960 Lew 252--16l2,956,026 10/1960 Lew 252161 3,345,031 10/1967 Stein et al. 2521523,346,629 10/ 1967 Broussalian 260-613 3,444,087 5/ 1969 Eccles et al252138 3,428,654 2/1969 Rubinfeld et a1. 260-367 LEON D. ROSDOL, PrimaryExaminer P. E. WILLIS, Assistant Examiner US. Cl. X.R. 252535, 536, 554

